LB-2 CAS Plane, Achtung, Jabo!

(WIP)

Description:

"Bad day. Very bad day."-Anonymous Terran Infantryman, Southern Front, 1943.

"This thing has probably fucked up more Juumans and Terrans than anything else in our inventory."-

"Oh how we absolutely loathed this plane."-Anonymous Juuman Admiral

Overview: The LB-2 was a dedicated dive bomber and ground attack plane

Armor and Survivability: The LB-2 carried over 1000 kilograms of armor, wrapped mostly around the engine cowling, cockpit and wing roots. The armor was meant to stop small arms fire and shrapnel from critically damaging the plane while occasionally providing protection from HMG bullets and the occasional glancing hit from a cannon or AA gun.

The fuel tanks were self-sealing and wrapped in ballistic nylon.


Designation: LB-2 Light Bomber, Land and Carrier Based

Dimensions:
Crew: 2 (Pilot, Bombardier)
Length: 12.05m
Wingspan: 15.50 m
Height: 4.05m
Empty Weight: 5,700kg
Loaded Weight: 6,900kg
Max Takeoff Weight: 9,100kg

Engine/Powertrain: AFE-18 Supercharged 18 cylinder radial driving a variable pitch 5 bladed propeller.

Cylinders: 18, two row
Displacement: 60 liters
Valvetrain: 4 valves per cylinder, double overhead camshaft.
Fuel System: Direct fuel injection
Induction System: 3 stage, 4 speed centrifugal supercharger
Boost: MW-50 tank mounted in rear of fuselage
Cooling: 70/30% water to ethylene glycol. Pressurized cooling system.
Weight: ~1200kg

Internal Fuel: 1000 liters in fuselage tanks + additional 500 liters in wing tanks (optional)
MW-50: 220 liters (15-18 minutes of MW-50 boost)

Power Output:
-2400 hp (Maximum continuous, @ 7000m)
-2800 hp (Takeoff/WEP)
-3500 hp (+MW-50 injection)

Performance:
Maximum speed: 350mph @ 11000m (563 km/hr)
Range: 1,500 km on internal fuel (2,600 km with drop tanks)
Combat Radius: 600 km
Service ceiling: 12,000m (+MW-50)

Control Authority (Dive): 610 mph (982 km/h)

Features:
-Self sealing fuel tanks covered in ballistic nylon
-Heavy armor
-4 piece plexiglas cockpit for 2 crew members
-Pressurized cockpit
-Ejection seat (retrofitted)

Equipment:
-Autopilot
-Radio
-Radio Navigation Suite
-Gyro stabilized gunsight
-Gyro stabilized bombsight in cockpit floor.

Armament:
-Base: 2x 25x200mm cannon in engine cowling, 2x 25x200mm cannon in wings, 175 rounds per cannon. Cannon fire at 800 rpm. 13 seconds of continuous fire.

Alternate #1: 2x VMW-212 40mm cannon in underwing gondolas, 24 rpg
-4x 15.5x121mm HMG, 2 in cowling, 1 ea. wing, 500 rpg.

Bomb Load: Up to 2000 kg of expendable stores may be carried. Typical load is 2x 250kg cluster bombs on the fuselage and 6x 155mm rockets on the wings.

you're carrying an actual ton of armor.

I can't see why a twincharger system would be of any use for an aircraft like this. I'd delete the supercharger and stick with the turbos.

The Il-2 carried 700kg of armor, the Il-10 carried 900 kg of armor. I haven't mentioned that the armor is a stressed element yet.

It's less great than it sounds. Stressing the armor doesn't save that much weight, while limiting armor effectiveness. So it's still mostly dead weight, your unarmored weight would be between 3500 and 3800kg.

MTOW reserve appears too high.

Range is totally overboard, it was <1000km for the era, and not enough weight allowance for externals anyway. Unless I'm totally misreading the era, but even then. Armor totally messes up your weight reserve.

All in all I'm quite sure you need a larger plane for everything you want here; 3000kg of external stores isn't even physically possible with given weights.

Doesn't making the armour part of the structure mean that quick repairs are a lot harder, because you now have to replace part of the airframe?

What it means in WWII context is that you just replace metal skin with thicker metal skin (armor). Still carried by a normal airframe. Calling it a stressed element isn't quite correct, in that it carries almost no load (the load is on the frame).

In any modern context you'd rather use aramid or ceramic armor that is not structural, but a lot more effective per unit weight. Except in very unusual cases when you're using a monocoque element, but that's a lot more limited in application.

It's going to be really hard to get that rate of fire with that monster shell in a gun light and compact to fit in wings and engine cowlings.

I'm not sure bombardier and rear gunner should be a combined role. To use the guns, the bombardier will have to be sitting backwards, but to use the bombsight he has to look forwards. So you'll have to either have room to crawl around in the fuselage or a complicated periscope arrangement that might be obscured by the bomb racks.

The rear gun armament also seems a little heavy to use effectively without powered mounts.

So it's a HS 129 that is heavier, faster, and can carry more bombs?

I think only the last aspect makes more sense for a close air support plane.

overhead cams are the preserve of V or inline engines as they are driven by a belt of the main crank, a radial is generally pushrod, if it is not a push rod, it will be sleeve valve, (like the Bristol Hercules). (still 4-stroke though).